The invention relates to a method for aromatising tobacco smoke drawn from a cigarette, a cigarette endpiece, in particular a cigarette filter for carrying out this method, and a use for the method.
In producing mentholated cigarettes, it is already known to spray for example the shredded tobacco, the cigarette packet or the acetate filter with a menthol solution during their manufacture. However, such methods have the drawback that the manufacture of mentholated cigarettes must be carried out isolated from the manufacture of other cigarettes because of the strong volatility of menthol on the one hand, and the strong affinity of tobacco for this latter, otherwise the other cigarettes will likewise have an additional taste. If the manufacture of mentholated cigarettes is done only in relatively small production quantities due to their limited demand, then the total production line has to be decontaminated after each changeover to nonmentholated cigarettes, and this is understandably extremely complicated and costly, because in addition to the cleaning costs, the production plant must remain shut down during the total cleaning time.
As an increasing number of lighter cigarettes, i.e. cigarettes with a low nicotine and tar content in the smoke are required, it could be advantageous to aromatise the smoke produced by such cigarettes for example by means of tobacco extract or synthetic tobacco aroma.
However the methods tried up to the present time all have the drawback that a relatively large amount of often very expensive aroma substance is necessary in order to obtain sufficient aromatising, and after a short time the aroma substance has evaporated and shows no further satisfactory action, so that such cigarettes can be stored only for an insufficient time.
The object of the present invention is to provide a method in which the aforesaid drawbacks are absent, i.e. which for example makes possible the manufacture of mentholated filter cigarettes without contaminating the production plant, requires relatively small quantities of aroma substances, is simple to use, and gives the thus aromatised cigarettes a long storability.
This object is attained in a method of the aforesaid type according to the invention, by using a porous magnesium silicate and/or magnesium silicate hydrate charged with aroma substances in the cigarette mouthpiece. It has been shown that granular porous magnesium silicate or magnesium silicate hydrate has an excellent adsorption capacity for storing aroma substances, and even when such aroma carriers charged with aroma substances are stored in open conditions for a time of several months, the evaporation of the stored aroma substance is so small that a sufficient quantity thereof is still present stored in the aroma carrier. On the other hand, when such an aroma carrier charged with aroma substances becomes located in a warm, moist smoke stream of a cigarette, a determined quantity of aroma substance is given up into the warm, moist smoke stream which flows past for each draw by the smoker on such a cigarette, as is desired.
It is advantageous if a synthetic tobacco aroma, a tobacco extract or menthol is used as the aroma substance.
It is advantageous to use a magnesium silicate or magnesium silicate hydrate with a magnesium content of at least 4 weight % and preferably 8 to 25 weight %, with respect to the dry matter.
It is further advantageous to use a magnesium silicate or magnesium silicate hydrate charged with 5 to 14 weight % and preferably 8 to 10 weight %, with respect to the uncharged magnesium silicate or hydrate. It is also advantageous if the magnesium silicate and/or magnesium silicate hydrate charged with aroma substances is worked into at least a part of the filter material intended for a cigarette filter, for example a double filter.
The present invention further relates to a cigarette end piece, in particular a cigarette end filter for carrying out the method according to the invention, characterised by comprising a chamber containing at least the magnesium silicate and/or magnesium silicate hydrate charged with aroma substances.
The present invention further relates to a use for the method according to the invention in mentholating tobacco smoke.
The advantages of the method according to the invention are described hereinafter with reference to the aromatising of smoke with menthol in comparison to other methods.